Computer/Embedded Technology


Putting Flash lifespan into perspective

21 September 2005 Computer/Embedded Technology

Most industrial PCs or single board computers (SBC) are fitted with CompactFlash sockets. This allows the system to boot and run from a CompactFlash instead of a hard disk drive. Compact Flashes are physically smaller and can handle shock and vibration much better than hard disk drives. They have simulated heads, sectors and cylinders just like normal hard disk drives, allowing the PC BIOS to treat them as normal hard disk drives.

Unfortunately, Flash devices have a limited number of write cycles, which often results in the non-selection of Flash as a data storage medium. Low-cost 'retail grade' compact Flashes can be specified to have as low as 100 000 write cycles. 'Industrial Grade' CompactFlash can be specified to have up to 3 million write cycles. In many cases, this might still seem low. Note that one write cycle means writing to the whole Flash once. If you write 100 KB at a time to a 100 MB Compact Flash, you would need to write this amount 1000 times to constitute one write cycle. Flash has wear levelling built into the design.

Example: Let us assume you have an Industrial Grade 1 GB CompactFlash of which the operating system takes up 250 MB (XPembedded, for example) and the remaining 750 MB is used for data storage. Now, you can write data blocks of 100 KB 7500 times to make up one write cycle (750 MB/0,1 MB). This means that you can do 3 million times 7500 writes of 100 KB before the Flash is used up. If you write once every 5 seconds (24/7) it will last 3E6 x 7500 x 5 seconds or 3567 years which is surely long enough (this is based on theory - actual result may vary a lot but even if one divides the time by 100, the period is still long enough for most applications.)

Flash lifespan can be increased further if you use an operating system such as XPembedded and select the EWF (enhanced write filter) option. This filters out writes to the Flash and redirects the written data to other locations such as system RAM. From time-to-time, the data can be copied from RAM onto the Flash, resulting in a huge saving in the number of writes to Flash. A noteworthy point, is that 'Flash lifespan' is normally not the first reason why a system fails.



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

First NVMe SSD Built with 8th-gen BiCS FLASH
EBV Electrolink Computer/Embedded Technology
KIOXIA recently announced the development and prototype demonstration of its new KIOXIA CM9 Series PCIe 5.0 NVMe SSDs, which incorporates CMOS directly Bonded to Array technology.

Read more...
QuecPi smart development board
iCorp Technologies Computer/Embedded Technology
The QuecPi Alpha smart MOB development board is Quectel’s smart development board based on Qualcomm’s QCS6490 high-performance 64-bit octa-core processor.

Read more...
Eskom announces PV registration extension
Computer/Embedded Technology
The South African Photovoltaic Industry Association has welcomed Eskom’s decision to extend its zero-registration fee policy and free smart meter installation for residential Small-Scale Embedded Generation customers until March 2026.

Read more...
Unlock enhanced wireless performance
Computer/Embedded Technology
Duxbury Networking has introduced Cambium Networks’ Deep Virtual Circuit (Deep VC) technology, a free upgrade for the PMP 450 platform that will transform wireless broadband performance across the country.

Read more...
Computing in industrial environments
Vepac Electronics Computer/Embedded Technology
The Panasonic Toughbook CF-33/CF33 Tablet is a 12,0-inch fully rugged device with hot-swappable twin batteries and highly configurable capabilities.

Read more...
DDR5 DRAM series
Vepac Electronics Computer/Embedded Technology
Innodisk has announced its DDR5 6400 DRAM series featuring the industry’s largest 64GB single-module capacity.

Read more...
Generate waveforms at 10 GS/s
Vepac Electronics Computer/Embedded Technology
New flagship arbitrary waveform generator cards from Spectrum Instrumentation generate waveforms with 2,5 GHz bandwidth and 16-bit vertical resolution.

Read more...
Quad-port 10GBASE-T controller
Rugged Interconnect Technologies Computer/Embedded Technology
he SN4-DJEMBE, available from Rugged Interconnect, is a networking adaptor card for CompactPCI Serial systems, equipped with four individual controllers for 10GBASE-T.

Read more...
HPE policy management platform
Computer/Embedded Technology
Duxbury Networking has announced the availability of the HPE Aruba ClearPass policy management platform, that enables business and personal devices to connect to an organisational level, in compliance with corporate security policies.

Read more...
IoT gateways
Brandwagon Distribution Computer/Embedded Technology
IoT Gateways are hardware and software devices that are responsible for collecting data from connected devices, managing communication between devices and the cloud, and processing and analysing the data before sending it to the cloud for further analysis.

Read more...